Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2023, Vol. 20, No. 6, pp. 80-91
On the importance of tidal correction for calculation of mean sea level surfaces from IMMOAD SSHA satellite altimetry data
G.V. Shevchenko
1, 2 , A.A. Romanov
3 1 Russian Federal Research Institute of Fisheries and Oceanography, Sakhalin Branch, Yuzhno-Sakhalinsk, Russia
2 Institute of Marine Geology and Geophysics FEB RAS, Yuzhno-Sakhalinsk, Russia
3 AO Central Research Institute for Machine Building, Korolev, Moscow Region, Russia
Accepted: 20.10.2023
DOI: 10.21046/2070-7401-2023-20-6-80-91
Utilizing observation data from four artificial Earth satellites (Integrated Multi-Mission Ocean Altimeter Datasets, Sea Surface Height Anomalies — IMMOAD SSHA) spanning from 1992 to 2022, average long-term variations in sea level anomalies were computed for different seasons and the entire period. These computations were conducted both with and without accounting for tidal corrections. Notably, employing tidal correction yielded values close to zero for the entire period within the study area, highlighting the effectiveness of the correction process. During winter, noticeable gradients in sea level anomalies were observed along the coasts of the Sea of Okhotsk and the Bering Sea, indicating intensified cyclonic circulation in these regions. Conversely, during summer, there were low sea level anomalies near these coasts, signifying the formation of opposing currents. Spring and autumn, on the other hand, did not exhibit pronounced gradients in sea level anomalies. Errors introduced by the residual tidal component exhibited similar spatial distributions across all seasons, with the highest values occurring in the Kuroshio zone and the bays in the northeastern and northwestern parts of the Sea of Okhotsk. The sea level anomalies, purged of residual tide effects, lack components that could distort the average sea level, both over the entire period and at specific intervals. This cleaned dataset can be employed in a wide array of oceanological studies.
Keywords: satellite altimetry, sea level anomalies, gradient, current, tide, Northwestern Pacific Ocean, Far Eastern seas
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